How do you handle payment? When is it due?

I definitely plan on using paypal so I can accept credit cards, but I'm just wondering how it should work as far as WHEN the client should pay.

This is how I put it on my website FAQ:
"After you sign your service agreement, I will email you a PayPal invoice and from there, you can pay your 50% deposit online with a credit or debit card to secure your date (a PayPal account is not required to do this). The remaining 50% of your total fee depends on the type of payment - if you are paying by cash, check, or money order, then payment is due upon the artist's arrival. If you are paying with a credit or debit card, then payment is due 48 hours prior to the event."

I'm just not sure about the 48 hours thing. Does this make sense or should I just send them an invoice after the event is over?

Also, is a 50% deposit too much? I was a bit reluctant to set it that high.

Thanks, guys! Starting a business (even a tiny one like this!) is quite an adventure so your help is appreciated.

I am cash or cheques only. The deposit varies from 50% to a max of $150.

My terms say on arrival... but that only occasionally happens. Generally at birthdays it is as I am leaving, and I count it in front of them.

Corporate are cheques and some have them to hand to me, some hand deliver to my house the next day because they forgot it, others only when pre-arranged mail it.

Most don't use paypal for the final payment for me, but one person has for a "corporate" gig (a small science centre day camp, is that really corporate?) the day before because she wouldn't be there at the event and wanted to be sure everything was taken care of.

I prefer to get it as soon as I get there, but it is usually at the end of the party or event. At a private event, I would never leave without payment. I have left ONE public event without payment because there wasn't a chance in hell of me finding one of the organizers when the whole thing was all over downtown and they were random people from the BIA.... I had to get to a party and if I wandered around downtown in clown, I'd get mobbed.